This invention relates to improvements in cooling systems and devices. Particularly, the invention relates to portable coolers useful for storing and transporting temperature sensitive items such as medicines, biological tissues and other perishables.
Some temperature sensitive medications require frequent administration and must be transported with the patient when traveling. Some of these, such as certain biologically based medications, in addition to being temperature sensitive are extremely costly. Activities, including travel, can be restricted by the need to medicate. Travel restrictions relate to the duration of travel and to conditions. Leaving some medications in a car during hot weather, even for short periods, may not be possible without degrading the safety, quality or effectiveness of the medication. On long trips medications are subjected to vagaries of travel that can make maintenance of specific temperature conditions doubtful.
Patients have resorted to transporting medications in small beverage containers, in ice or with various cold packs. Insulated water and beverage carriers are commandeered for medications on occasion. These provide a measure of cool storage but not the longevity, degree of cooling or convenience frequently needed. In all these cases the duration of safe storage is limited by the insulating character of the carrier, the amount of cold packing material and the temperature maintenance requirements of a particular medication.
Portable beverage and water coolers have been provided with cooling systems, such as thermoelectric heat transfer modules, that extend cooling times but these operate only when a power source is available. In some circumstances power sources are unavailable, inconvenient or prohibited.
Examples of coolers of the types mentioned above are described in U.S. Pat. No. 6,003,318, U.S. Patent Pub. No. US2003/0115902 A1 and U.S. Patent Pub. No. US2009/0049845 A1.
Examples of temperature sensitive medications are insulin and Enbrel®. Insulin, for example, is administered at scheduled times and for many patients also must be more or less continuously available for unscheduled administration. A convenient mode of administering drugs is by a drug administering pen. The pen contains an amount of injectable drug sufficient for one or several doses and delivers a measured dose of medication with each administration. A traveler would need to carry several pens to have a quantity of medication sufficient for a long trip. In such a case medication must be stored and transported for an extended time, frequently including periods without power for operating a cooling system.